Re: [PATCH v5 07/13] perf/x86/amd: make Zen3 branch sampling opt-in

From: Peter Zijlstra
Date: Thu Jan 27 2022 - 07:52:04 EST


On Wed, Jan 26, 2022 at 03:34:48PM -0800, Stephane Eranian wrote:
> This patch adds a kernel config option to make support
> for AMD Zen3 Branch Sampling (BRS) an opt-in compile
> time option.
>
> Signed-off-by: Stephane Eranian <eranian@xxxxxxxxxx>
> ---
> arch/x86/events/Kconfig | 8 ++++++
> arch/x86/events/amd/Makefile | 3 ++-
> arch/x86/events/perf_event.h | 49 ++++++++++++++++++++++++++++--------
> 3 files changed, 49 insertions(+), 11 deletions(-)
>
> diff --git a/arch/x86/events/Kconfig b/arch/x86/events/Kconfig
> index d6cdfe631674..1dc002ef66da 100644
> --- a/arch/x86/events/Kconfig
> +++ b/arch/x86/events/Kconfig
> @@ -44,4 +44,12 @@ config PERF_EVENTS_AMD_UNCORE
>
> To compile this driver as a module, choose M here: the
> module will be called 'amd-uncore'.
> +
> +config PERF_EVENTS_AMD_BRS
> + depends on PERF_EVENTS && CPU_SUP_AMD
> + tristate "AMD Zen3 Branch Sampling support"

tristate ?!